// See the file "COPYING" in the main distribution directory for copyright.

#include "zeek/zeekygen/utils.h"

#include <sys/stat.h>
#include <algorithm>
#include <cerrno>

#include "zeek/Func.h"
#include "zeek/ID.h"
#include "zeek/Reporter.h"
#include "zeek/Scope.h"
#include "zeek/Val.h"
#include "zeek/plugin/Manager.h"

using namespace std;

namespace zeek::zeekygen::detail {

bool prettify_params(string& s) {
    size_t identifier_start_pos = 0;
    bool in_identifier = false;
    string identifier;

    for ( size_t i = 0; i < s.size(); ++i ) {
        char next = s[i];

        if ( ! in_identifier ) {
            // Pass by leading whitespace.
            if ( isspace(next) )
                continue;

            // Only allow alphabetic and '_' as first char of identifier.
            if ( isalpha(next) || next == '_' ) {
                identifier_start_pos = i;
                identifier += next;
                in_identifier = true;
                continue;
            }

            // Don't need to change anything.
            return false;
        }

        // All other characters of identifier are alphanumeric or '_'.
        if ( isalnum(next) || next == '_' ) {
            identifier += next;
            continue;
        }

        if ( next == ':' ) {
            if ( i + 1 < s.size() && s[i + 1] == ':' ) {
                // It's part of an identifier's namespace scoping.
                identifier += next;
                identifier += s[i + 1];
                ++i;
                continue;
            }

            // Prettify function param/return value reST markup.
            string subst;

            if ( identifier == "Returns" )
                subst = ":returns";
            else
                subst = ":param " + identifier;

            s.replace(identifier_start_pos, identifier.size(), subst);
            return true;
        }

        // Don't need to change anything.
        return false;
    }

    return false;
}

bool is_public_api(const zeek::detail::ID* id) {
    return (id->Scope() == zeek::detail::SCOPE_GLOBAL) || (id->Scope() == zeek::detail::SCOPE_MODULE && id->IsExport());
}

time_t get_mtime(const string& filename) {
    struct stat s;

    if ( stat(filename.c_str(), &s) < 0 )
        reporter->InternalError("Zeekygen failed to stat file '%s': %s", filename.c_str(), strerror(errno));

    return s.st_mtime;
}

string make_heading(const string& heading, char underline) {
    return heading + "\n" + string(heading.size(), underline) + "\n";
}

size_t end_of_first_sentence(const string& s) {
    size_t rval = 0;

    while ( (rval = s.find_first_of('.', rval)) != string::npos ) {
        if ( rval == s.size() - 1 )
            // Period is at end of string.
            return rval;

        if ( isspace(s[rval + 1]) )
            // Period has a space after it.
            return rval;

        // Period has some non-space character after it, keep looking.
        ++rval;
    }

    return rval;
}

bool is_all_whitespace(const string& s) {
    auto it = std::ranges::find_if(s, [](char c) { return ! isspace(c); });
    return it == s.end();
}

string redef_indication(const string& from_script) {
    return util::fmt("(present if :doc:`/scripts/%s` is loaded)", from_script.c_str());
}

std::string normalize_script_path(std::string_view path) {
    if ( auto p = plugin_mgr->LookupPluginByPath(path) ) {
        auto rval = util::detail::normalize_path(path);
        auto prefix = util::SafeBasename(p->PluginDirectory()).result;

        // Collision avoidance when there's no _ in the plugin basename such
        // as when using ./build within a plugin checkout for testing. Include
        // the parent in the normalized path assuming it's unique.
        if ( prefix.find('_') == std::string::npos ) {
            auto parent = util::SafeBasename(util::SafeDirname(p->PluginDirectory()).result).result;
            prefix = parent + "/" + prefix;
        }

        return prefix + "/" + rval.substr(p->PluginDirectory().size() + 1);
    }

    return util::detail::without_zeekpath_component(path);
}

std::optional<std::string> source_code_range(const zeek::detail::ID* id) {
    const auto& type = id->GetType();

    if ( ! type )
        return {};

    // Some object locations won't end up capturing concrete syntax of closing
    // braces on subsequent line -- of course that doesn't have to always be
    // case, but it's true for current code style and the possibility of
    // capturing an extra line of context is not harmful (human reader shouldn't
    // be too confused by it).
    int extra_lines = 0;
    const zeek::detail::Location* loc = &zeek::detail::no_location;

    switch ( type->Tag() ) {
        case TYPE_FUNC: {
            const auto& v = id->GetVal();

            if ( v && v->AsFunc()->GetBodies().size() == 1 ) {
                // Either a function or an event/hook with single body can
                // report that single, continuous range.
                loc = v->AsFunc()->GetBodies()[0].stmts->GetLocationInfo();
                ++extra_lines;
            }
            else
                loc = id->GetLocationInfo();
        } break;
        case TYPE_ENUM:
            // Fallthrough
        case TYPE_RECORD:
            if ( id->IsType() ) {
                loc = type->GetLocationInfo();

                if ( std::string_view{loc->FileName()}.ends_with(".bif.zeek") )
                    // Source code won't be available to reference, so fall back
                    // to identifier location which may actually be in a regular
                    // .zeek script.
                    loc = id->GetLocationInfo();
                else
                    ++extra_lines;
            }
            else
                loc = id->GetLocationInfo();

            break;
        default: loc = id->GetLocationInfo(); break;
    }

    if ( loc == &zeek::detail::no_location )
        return {};

    return util::fmt("%s %d %d", normalize_script_path(loc->FileName()).data(), loc->FirstLine(),
                     loc->LastLine() + extra_lines);
}

} // namespace zeek::zeekygen::detail
